Change the channel with Logitech Harmony: "OK Google, turn the TV to the Travel Channel."

Customize trigger phrases for IFTTT. For example: "OK Google, let's get this party started."

Third-party Actions

Earlier this month, Google rolled out what it calls Actions for Google Assistant. These are third-party services and integrations that work much like Alexa skills, except you don't have to activate them one by one. Actions are enabled by default.
You can find the full list of Actions in the Google Home app by going to More settings > Services. You will also find sample invocations there, which will tell you how to interact with the different services available.

21 Blackjack: "OK Google, let me talk to 21 Blackjack."

Best Dad Jokes: "OK Google, talk to Best Dad Jokes."

Domino's: "OK Google, talk to Domino's and get my Easy Order."

Product Hunt: "OK Google, talk to Product Hunt."

Tender: "OK Google, can I talk to Tender about drinks like an old fashioned?"